Obviously we can't reveal the exact locations of the schools or dojo where Fudebakudo is taught, because it is a secret martial art. Some people devote a lifetime searching for the right teacher, but it's probably simpler just to buy the book.
Nonetheless, Fudebakudo is widespread. So if you're looking for a teacher, it might be useful to study the global distribution first. Or try asking anyone you see who is wearing the T-shirt. If all else fails, maybe some of these people can help.